In the search for nursing knowledge for practical, professional, academic and personal purposes, criteria for its identification need to be developed. The conceptualization of a nursing perspective emerges as a primary and fundamental task in this endeavour. Current attempts to develop nursing knowledge are often irrelevant, arbitrary, and inappropriate. The conviction that empirical methods of investigation alone cannot produce nursing knowledge has led to infrequent, generally fragmented and often confused attempts to clarify the meaning of philosophical enquiries in nursing. Most claims to a 'philosophy of nursing1 misrepresent ideological statements as philosophical concerns and obscure the essential meaning of philosophical enquiries. 'Nursing ethics' fail to engage in the criticism and analysis of moral arguments. Theory construction and development indicate essential philosophical concerns in nursing. It seems necessary to examine philosophers' explanations of the purposes of philosophy, the nature of philosophical problems, the methods used in philosophical enquiries, the contents of the discipline of philosophy, and its relationship with other disciplines. The potential development of nursing knowledge by relevant philosophical enquiries demands that four fundamental philosophical tasks be accomplished, namely, limiting the search for knowledge, thinking methodically and systematically about nursing, identifying the philosophical demands of the research process, and constructing and developing nursing theories. The essential nature of philosophical enquiries demands that all nurses need to participate at some level and to some extent in accomplishing these four fundamental tasks, if nursing is to be established as a practice discipline.